1. Field of the Invention
The present general inventive concept relates to a printing medium supplying apparatus and an image forming apparatus having the same, and more particularly, to a printing medium supplying apparatus and an image forming apparatus having the same including a printing medium aligning unit.
2. Description of the Related Art
An image forming apparatus forms an image on a printing medium, and may be classified as an ink jet type discharging an ink, an electrophotographic type having charging, exposing, developing, transferring and cleaning processes, and a thermal transfer type using an ink ribbon.
FIG. 1 is a schematic sectional view of a conventional image forming apparatus 1 of the electrophotographic type.
The conventional image forming apparatus 1 includes a printing medium supplying unit 10, a printing medium aligning unit 20, an image forming unit 30, a fusing unit 40, a discharging unit 50, a printing medium transporting unit 60 and a manual paper supplying unit 70.
The printing medium supplying unit 10 includes a casing 11, a plate 13 accommodated to the casing 11 to be loaded with a printing medium P, an elastic member 15 elastically supporting the plate 13, and a friction pad 17 preventing the printing medium P loaded on the plate 13 from being doubly transported by means of a friction force. Also, the printing medium supplying unit 10 slidably moves in a sliding direction A to be detachably mounted to a main body 2 of the image forming apparatus 1. The printing medium P loaded on the plate 13 is picked up by a pickup roller 12, and is individually separated by the friction pad 17 to be transported to feeding rollers 53 and 55.
The printing medium aligning unit 20 includes a pair of aligning rollers 23 and 25. A front end part of the printing medium P transported by the feeding rollers 53 and 55 bumps against the pair of rollers 23 and 25 maintaining a stop state so that the printing medium P can be aligned.
After aligning the printing medium P, the aligning rollers 23 and 25 rotate to supply the aligned printing medium P to the printing medium transporting unit 60.
The printing medium transporting unit 60 includes a belt 61, and a driving roller 63 and driven rollers 65 circulating the belt 61 in orbit. The printing medium P transported by the aligning rollers 23 and 25 is attracted to the belt 61 to pass between a photosensitive body 37 and a transferring roller 39 of the image forming unit 30.
The image forming unit 30 may include a plurality of developing cartridges 30Y, 30M, 30C and 30K, and a plurality of transferring rollers 39. Each developing cartridge 30Y, 30M, 30C and 30K respectively stores yellow, magenta, cyan and black toners, and accommodates the photosensitive body 37, a charging roller 35, a developing roller 33 and a supplying roller 31. The charging roller 35 charges a surface of the photosensitive body 37, and the photosensitive body 37 having the charged surface is exposed by an exposing unit (not illustrated) so that an electrostatic latent image can be formed on the surface. The supplying roller 31 supplies the stored toner to the developing roller 33, and the developing roller 33 develops the electrostatic latent image with the supplied toner.
The electrostatic latent image developed with the toner is transferred to the printing medium P by the transferring roller 39, and then passes through the fusing unit 40 including a heating roller 41 and a pressing roller 43 to be fused on the printing medium P. The printing medium P may be supplied to the image forming unit 30 by the manual paper supplying unit 70 instead of the printing medium supplying unit 10.
The manual paper supplying unit 70 includes a manual supplying supporter 71 on which the printing medium P is loaded, a manual pickup roller 77 picking up the printing medium P of the manual supplying unit 71, and feeding rollers 73 and 75 transporting the picked up printing medium P to the printing medium aligning unit 20.
Although the conventional printing medium aligning unit 20 is securely coupled to a frame (not illustrated) inside the image forming apparatus 1, the printing medium supplying unit 10 is needed to be detachably mounted to the main body 2 to load the printing medium P on the plate 13. Accordingly, since it is necessary that the printing medium aligning unit 20 and the printing medium supplying unit 10 are disposed without interfering with each other, it is difficult to make the image forming apparatus 1 small.
Also, if the printing medium P is jammed between the manual paper supplying unit 70 and the printing medium aligning unit 20, since the printing medium aligning unit 20 is securely disposed on the frame, it is difficult to remove the jammed printing medium P.